河套灌区间作系统根系土壤水盐运移机理及间作优势研究

为探究河套灌区春小麦/春玉米间作系统两作物间水分相互利用量、土壤盐分运移机理和地下部分对间作优势的贡献率及种间相对竞争能力等问题,采用根系分隔法进行了田间试验研究。结果表明:间作小麦利用了玉米侧214.0~224.5 m3/hm2的水量,间作玉米利用了小麦侧108.1~125.2 m3/hm2的水量。间作模式下根系在土壤空间的叠加利用效应可以降低0.2%~1.5%的小麦带土壤EC均值,2.7%~3.1%的玉米带土壤EC均值;水分的流通可使间作小麦带土壤EC均值降低4.4%~4.5%,使间作玉米带土壤EC均值降低3.4%~5.2%。河套灌区小麦/玉米间作系统的产量优势为27.7%~33.1%,其中20.4%~26.6%来源于地下部分的补偿作用,6.5%~7.2%来自于地上部分。间作产量优势中的10.0%~15.8%产生于间作根系对土壤空间的叠加利用,而水分与养分在小麦带与玉米带间的补偿效应为10.4%~10.8%。

Research on the mechanism of water and salt transport in root soil and the advantage of intercropping system in Hetao irrigation district

In order to study the issues on the mutual water use efficiency,the mechanism of soil salt transport, the contribution rate of underground part to intercropping advantage and the relative competitiveness of intercropping in spring wheat-spring maize intercropping system in Hetao irrigation area, a field experiment has been conducted on the base of root partition method. The results show that the intercropping wheat utilized 214.0~224.5m³/hm² of water by the side of maize. Meanwhile, the intercropping maize utilized 108.1~125.2m³/hm² of water by the side of wheat. The mean value of root soil EC in wheat and maize belts could reduce 0.2%~1.5% and 2.7%~3.1%, respectively, by the superposition utilization effect of soil internal space under the intercropping mode. The water circulation is another factor that could reduce the mean value of root soil EC, with a decrease of 4.4%~4.5% and 3.4%~5.2% in the intercropping wheat and maize belts, respectively. The yield advantage of wheat-maize intercropping system in Hetao irrigation district is 27.7%~33.1%, with 20.4%~26.6% attributed to the compensation effect of underground part, and 6.5%~7.2% is attributed to the effect of aboveground part. The 10.0%~15.8% of intercropping yield advantage results from superposition utilization of soil internal space by intercropping root,and the compensation effect of water and nutrient between the wheat and maize belts is 10.4%~10.8%.